Anomaly detection and root cause analysis in a multi-tenant environment

ABSTRACT

System and methods are described for anomaly detection and root cause analysis in database systems, such as multi-tenant environments. In one implementation, a method comprises receiving an activity signal representative of resource utilization within a multi-tenant environment; detecting a plurality of anomalies in the activity signal; computing a priority score for each of the plurality of anomalies; correlating at least a subset of the plurality of anomalies to one or more performance metrics of the multi-tenant environment; and transmitting a remediation signal to one or more devices in the multi-tenant environment based on the correlations and the priority scores.

COPYRIGHT NOTICE

A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the United States Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.

TECHNICAL FIELD

The present disclosure relates to root cause analysis in database systems.

BACKGROUND

“Cloud computing” services provide shared resources, software, and information to computers and other devices upon request or on demand. Multi-tenant environments are a type of cloud computing architecture that often manage large quantities of incoming data from multiple sources and allocate computing resources among numerous users on a daily basis. By their nature, multi-tenant environments often experience unexpected surges in demand, which can affect different tiers of the environment in different ways and at different times. Consequently, it is exceedingly difficult for users to manually patrol the environment for regressions and abnormalities.

BRIEF DESCRIPTION OF THE DRAWINGS

The included drawings are for illustrative purposes and serve to provide examples of possible structures and operations for the disclosed inventive systems, apparatus, methods, and computer-readable storage media. These drawings in no way limit any changes in form and detail that may be made by one skilled in the art without departing from the spirit and scope of the disclosed implementations.

FIG. 1A shows a block diagram of an example environment in which an on-demand database service can be used according to some implementations.

FIG. 1B shows a block diagram of example implementations of elements of FIG. 1A and example interconnections between these elements according to some implementations.

FIG. 2A shows a system diagram of example architectural components of an on-demand database service environment according to some implementations.

FIG. 2B shows a system diagram further illustrating example architectural components of an on-demand database service environment according to some implementations.

FIG. 3 illustrates a diagrammatic representation of a machine in the exemplary form of a computer system within which one or more implementations may be carried out.

FIG. 4 illustrates an exemplary process flow for anomaly detection, prioritization, and correlation according to some implementations.

FIG. 5A illustrates the detection of a spike anomaly according to some implementations.

FIG. 5B illustrates the detection of a slope change anomaly according to some implementations.

FIG. 5C illustrates the detection of a level shift anomaly according to some implementations.

FIG. 5D illustrates the detection of a host imbalance anomaly according to some implementations.

FIG. 6 illustrates an exemplary user interface for visualizing anomalies and their correlations to performance metrics according to some implementations.

FIG. 7 is a flow diagram illustrating an exemplary method for detecting anomalies and performing root cause analysis in a multi-tenant environment according to some implementations.

DETAILED DESCRIPTION

The implementations described herein relate to anomaly detection and root cause analysis in database systems, such as multi-tenant environments. Specifically, certain implementations relate to an anomaly detection system that identifies relevant changes in infrastructure performance as they relate to pod-level or host-level trends in key performance metrics. The system monitors performance data (i.e., as an activity signal) and identifies different types of anomalies that may be present based on various measures, such as level shifts, slope-changes, spikes, and load imbalances. Anomalies may be prioritized based on a combination of these measures, which provides an indication of whether a given anomaly is a one-time occurrence or the symptom of an ongoing trend. Anomalies detected over a particular time duration may be correlated to known events also occurring during or close to that time duration to identify the likely root cause. In addition, to distinguish anomalies from normal (“organic”) resource utilization, a baseline signal (which may correspond to actual or anticipated resource utilization) is removed from the activity signal to reveal features in the activity signal that are not part of the baseline signal. This approach allows for anomalies to be isolated and correlated to particular events, conditions, or trends, which may be subsequently used to trigger remedial actions.

An anomaly in multi-tenant environments that may be important to detect early are sudden increases in usage of a particular feature in an organization, the consumption of which can affect other organizations maintained on the same pod. The effect appears as an increase in application central processing unit (CPU) utilization, which is difficult to distinguish from an increase in CPU utilization attributable to organic usage (i.e., an increase in workload) or, for example, a software release regression. Detecting anomalies early would alleviate the pod-level capacity issues and improve the customer experience of the organizations in the pod. Moreover, such detection can be used to trigger automatic capacity additions, hardware refreshes, or workload redistribution.

In general, multiple organizations within the multi-tenant environment consume different resources from different tiers that impact each other in terms of the total amount of computing resources available. When an issue arises in one of these tiers, it is difficult to patrol infrastructure points at any given point in time. Currently, this requires capacity planners and engineers to manually patrol the infrastructure to detect anomalies, as current systems lack the ability to do so. The implementations described herein address these and other limitations of current systems by allowing capacity planners and engineers to keep up with frequent unexpected surges in customer demand that occur within the multi-tenant environment by correlating them with the most likely causes.

Additional advantages of the implementations described herein over current systems include, but are not limited to: (1) prioritizing detected anomalies to focus on performance changes with severe implications while removing false-positives; (2) enabling automated load-balance remediation in response to correlating anomalies with hardware-related load imbalances; and (3) providing a user-interface to visualize anomalies, their prioritization, and their correlations with events, conditions, or trends in the multi-tenant environment. By triggering automated remediation, the implementations enable capacity planners and engineers to apply and maintain best practices policies. Historical anomalies allow capacity planners and engineers to focus on recurring regressions and abnormalities, providing an opportunity to invest in problematic areas that are continually flagged so that best practices can be revised accordingly. This becomes increasingly important as the scale of infrastructure data grows each year and, with it, the number of use cases for automated anomaly detection in the multi-tenant environment.

As used herein, an “anomaly” refers to any quantifiable characteristic in an activity signal that may be indicative of one or more unexpected events, conditions, or trends in a multi-tenant environment.

Also as used herein, “activity signal” refers to any signal representative of finite values of a monitored metric (e.g., resource utilization, CPU processing time, number of active users, etc.) measured over time, which may correspond to a specific underlying time period (e.g., a date range, hours during a particular day, etc.).

Examples of systems, apparatuses, computer-readable storage media, and methods according to the disclosed implementations are described in this section. These examples are being provided solely to add context and aid in the understanding of the disclosed implementations. It will thus be apparent to one skilled in the art that the disclosed implementations may be practiced without some or all of the specific details provided. In other instances, certain process or method operations, also referred to herein as “blocks,” have not been described in detail in order to avoid unnecessarily obscuring the disclosed implementations. Other implementations and applications also are possible, and as such, the following examples should not be taken as definitive or limiting either in scope or setting.

In the following detailed description, references are made to the accompanying drawings, which form a part of the description and in which are shown, by way of illustration, specific implementations. Although these disclosed implementations are described in sufficient detail to enable one skilled in the art to practice the implementations, it is to be understood that these examples are not limiting, such that other implementations may be used and changes may be made to the disclosed implementations without departing from their spirit and scope. For example, the blocks of the methods shown and described herein are not necessarily performed in the order indicated in some other implementations. Additionally, in some other implementations, the disclosed methods may include more or fewer blocks than are described. As another example, some blocks described herein as separate blocks may be combined in some other implementations. Conversely, what may be described herein as a single block may be implemented in multiple blocks in some other implementations. Additionally, the conjunction “or” is intended herein in the inclusive sense where appropriate unless otherwise indicated; that is, the phrase “A, B, or C” is intended to include the possibilities of “A,” “B,” “C,” “A and B,” “B and C,” “A and C,” and “A, B, and C.”

The words “example” or “exemplary” are used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as an “example” or “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects or designs. Rather, use of the words “example” or “exemplary” is intended to present concepts in a concrete fashion.

In addition, the articles “a” and “an” as used herein and in the appended claims should generally be construed to mean “one or more” unless specified otherwise or clear from context to be directed to a singular form. Reference throughout this specification to “an implementation,” “one implementation,” “some implementations,” or “certain implementations” indicates that a particular feature, structure, or characteristic described in connection with the implementation is included in at least one implementation. Thus, the appearances of the phrase “an implementation,” “one implementation,” “some implementations,” or “certain implementations” in various locations throughout this specification are not necessarily all referring to the same implementation.

Some portions of the detailed description may be presented in terms of algorithms and symbolic representations of operations on data bits within a computer memory. These algorithmic descriptions and representations are the manner used by those skilled in the data processing arts to most effectively convey the substance of their work to others skilled in the art. An algorithm is herein, and generally, conceived to be a self-consistent sequence of steps leading to a desired result. The steps are those requiring physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, or otherwise manipulated. It has proven convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like.

It should be borne in mind, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise as apparent from the following discussion, it is appreciated that throughout the description, discussions utilizing terms such as “receiving,” “retrieving,” “transmitting,” “computing,” “generating,” “processing,” “reprocessing,” “adding,” “subtracting,” “multiplying,” “dividing,” “optimizing,” “calibrating,” “detecting,” “performing,” “analyzing,” “determining,” “enabling,” “identifying,” “modifying,” “transforming,” “applying,” “aggregating,” “extracting,” “registering,” “querying,” “populating,” “hydrating,” “updating,” “mapping,” “causing,” “storing,” “prioritizing,” “queuing,” “managing,” “comparing,” “removing,” “assigning,” “correlating,” “selecting,” or the like, refer to the actions and processes of a computer system, or similar electronic computing device, that manipulates and transforms data represented as physical (e.g., electronic) quantities within the computer system's registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission, or display devices.

The specific details of the specific aspects of implementations disclosed herein may be combined in any suitable manner without departing from the spirit and scope of the disclosed implementations. However, other implementations may be directed to specific implementations relating to each individual aspect, or specific combinations of these individual aspects. Additionally, while the disclosed examples are often described herein with reference to an implementation in which an on-demand database service environment is implemented in a system having an application server providing a front end for an on-demand database service capable of supporting multiple tenants, the present implementations are not limited to multi-tenant databases or deployment on application servers. Implementations may be practiced using other database architectures, i.e., ORACLE®, DB2® by IBM, and the like without departing from the scope of the implementations claimed. Moreover, the implementations are applicable to other systems and environments including, but not limited to, client-server models, mobile technology and devices, wearable devices, and on-demand services.

It should also be understood that some of the disclosed implementations can be embodied in the form of various types of hardware, software, firmware, or combinations thereof, including in the form of control logic, and using such hardware or software in a modular or integrated manner. Other ways or methods are possible using hardware and a combination of hardware and software. Any of the software components or functions described in this application can be implemented as software code to be executed by one or more processors using any suitable computer language such as, for example, C, C++, Java™ (which is a trademark of Sun Microsystems, Inc.), or Perl using, for example, existing or object-oriented techniques. The software code can be stored as non-transitory instructions on any type of tangible computer-readable storage medium (referred to herein as a “non-transitory computer-readable storage medium”). Examples of suitable media include random access memory (RAM), read-only memory (ROM), magnetic media such as a hard-drive or a floppy disk, or an optical medium such as a compact disc (CD) or digital versatile disc (DVD), flash memory, and the like, or any combination of such storage or transmission devices. Computer-readable media encoded with the software/program code may be packaged with a compatible device or provided separately from other devices (for example, via Internet download). Any such computer-readable medium may reside on or within a single computing device or an entire computer system, and may be among other computer-readable media within a system or network. A computer system, or other computing device, may include a monitor, printer, or other suitable display for providing any of the results mentioned herein to a user.

The disclosure also relates to apparatuses, devices, and system adapted/configured to perform the operations herein. The apparatuses, devices, and systems may be specially constructed for their required purposes, may be selectively activated or reconfigured by a computer program, or some combination thereof.

Example System Overview

FIG. 1A shows a block diagram of an example of an environment 10 in which an on-demand database service can be used in accordance with some implementations. The environment 10 includes user systems 12, a network 14, a database system 16 (also referred to herein as a “cloud-based system”), a processor system 17, an application platform 18, a network interface 20, tenant database 22 for storing tenant data 23, system database 24 for storing system data 25, program code 26 for implementing various functions of the database system 16, and process space 28 for executing database system processes and tenant-specific processes, such as running applications as part of an application hosting service. In some other implementations, environment 10 may not have all of these components or systems, or may have other components or systems instead of, or in addition to, those listed above.

In some implementations, the environment 10 is an environment in which an on-demand database service exists. An on-demand database service, such as that which can be implemented using the database system 16, is a service that is made available to users outside an enterprise (or enterprises) that owns, maintains, or provides access to the database system 16. An “enterprise” refers generally to a company or organization that owns one or more data centers that host various services and data sources. A “data center” refers generally to a physical location of various servers, machines, and network components utilized by an enterprise.

As described above, such users generally do not need to be concerned with building or maintaining the database system 16. Instead, resources provided by the database system 16 may be available for such users' use when the users need services provided by the database system 16; that is, on the demand of the users. Some on-demand database services can store information from one or more tenants into tables of a common database image to form a multi-tenant database system (MTS). The term “multi-tenant database system” can refer to those systems in which various elements of hardware and software of a database system may be shared by one or more customers or tenants. For example, a given application server may simultaneously process requests for a great number of customers, and a given database table may store rows of data such as feed items for a potentially much greater number of customers. A database image can include one or more database objects. A relational database management system (RDBMS) or the equivalent can execute storage and retrieval of information against the database object(s).

Application platform 18 can be a framework that allows the applications of the database system 16 to execute, such as the hardware or software infrastructure of the database system 16. In some implementations, the application platform 18 enables the creation, management and execution of one or more applications developed by the provider of the on-demand database service, users accessing the on-demand database service via user systems 12, or third party application developers accessing the on-demand database service via user systems 12.

In some implementations, the database system 16 implements a web-based customer relationship management (CRM) system. For example, in some such implementations, the database system 16 includes application servers configured to implement and execute CRM software applications as well as provide related data, code, forms, renderable web pages, and documents and other information to and from user systems 12 and to store to, and retrieve from, a database system related data, objects, and Web page content. In some MTS implementations, data for multiple tenants may be stored in the same physical database object in tenant database 22. In some such implementations, tenant data is arranged in the storage medium(s) of tenant database 22 so that data of one tenant is kept logically separate from that of other tenants so that one tenant does not have access to another tenant's data, unless such data is expressly shared. The database system 16 also implements applications other than, or in addition to, a CRM application. For example, the database system 16 can provide tenant access to multiple hosted (standard and custom) applications, including a CRM application. User (or third party developer) applications, which may or may not include CRM, may be supported by the application platform 18. The application platform 18 manages the creation and storage of the applications into one or more database objects and the execution of the applications in one or more virtual machines in the process space of the database system 16.

According to some implementations, each database system 16 is configured to provide web pages, forms, applications, data, and media content to user (client) systems 12 to support the access by user systems 12 as tenants of the database system 16. As such, the database system 16 provides security mechanisms to keep each tenant's data separate unless the data is shared. If more than one MTS is used, they may be located in close proximity to one another (for example, in a server farm located in a single building or campus), or they may be distributed at locations remote from one another (for example, one or more servers located in city A and one or more servers located in city B). As used herein, each MTS could include one or more logically or physically connected servers distributed locally or across one or more geographic locations. Additionally, the term “server” is meant to refer to a computing device or system, including processing hardware and process space(s), an associated storage medium such as a memory device or database, and, in some instances, a database application, such as an object-oriented database management system (OODBMS) or a relational database management system (RDBMS), as is well known in the art. It should also be understood that “server system” and “server” are often used interchangeably herein. Similarly, the database objects described herein can be implemented as part of a single database, a distributed database, a collection of distributed databases, a database with redundant online or offline backups or other redundancies, etc., and can include a distributed database or storage network and associated processing intelligence.

The network 14 can be or include any network or combination of networks of systems or devices that communicate with one another. For example, the network 14 can be or include any one or any combination of a local area network (LAN), wide area network (WAN), telephone network, wireless network, cellular network, point-to-point network, star network, token ring network, hub network, or other appropriate configuration. The network 14 can include a Transfer Control Protocol and Internet Protocol (TCP/IP) network, such as the global internetwork of networks often referred to as the “Internet” (with a capital “I”). The Internet will be used in many of the examples herein. However, it should be understood that the networks that the disclosed implementations can use are not so limited, although TCP/IP is a frequently implemented protocol.

The user systems 12 can communicate with the database system 16 using TCP/IP and, at a higher network level, other common Internet protocols to communicate, such as the Hyper Text Transfer Protocol (HTTP), Hyper Text Transfer Protocol Secure (HTTPS), File Transfer Protocol (FTP), Apple File Service (AFS), Wireless Application Protocol (WAP), etc. In an example where HTTP is used, each user system 12 can include an HTTP client commonly referred to as a “web browser” or simply a “browser” for sending and receiving HTTP signals to and from an HTTP server of the database system 16. Such an HTTP server can be implemented as the sole network interface 20 between the database system 16 and the network 14, but other techniques can be used in addition to or instead of these techniques. In some implementations, the network interface 20 between the database system 16 and the network 14 includes load sharing functionality, such as round-robin HTTP request distributors to balance loads and distribute incoming HTTP requests evenly over a number of servers. In MTS implementations, each of the servers can have access to the MTS data; however, other alternative configurations may be used instead.

The user systems 12 can be implemented as any computing device(s) or other data processing apparatus or systems usable by users to access the database system 16. For example, any of user systems 12 can be a desktop computer, a work station, a laptop computer, a tablet computer, a handheld computing device, a mobile cellular phone (for example, a “smartphone”), or any other Wi-Fi-enabled device, WAP-enabled device, or other computing device capable of interfacing directly or indirectly to the Internet or other network. When discussed in the context of a user, the terms “user system,” “user device,” and “user computing device” are used interchangeably herein with one another and with the term “computer.” As described above, each user system 12 typically executes an HTTP client, for example, a web browsing (or simply “browsing”) program, such as a web browser based on the WebKit platform, Microsoft's Internet Explorer browser, Netscape's Navigator browser, Opera's browser, Mozilla's Firefox browser, or a WAP-enabled browser in the case of a cellular phone, personal digital assistant (PDA), or other wireless device, allowing a user (for example, a subscriber of on-demand services provided by the database system 16) of the user system 12 to access, process, and view information, pages, and applications available to it from the database system 16 over the network 14.

Each user system 12 also typically includes one or more user input devices, such as a keyboard, a mouse, a trackball, a touch pad, a touch screen, a pen or stylus, or the like, for interacting with a GUI provided by the browser on a display (for example, a monitor screen, liquid crystal display (LCD), light-emitting diode (LED) display, etc.) of the user system 12 in conjunction with pages, forms, applications, and other information provided by the database system 16 or other systems or servers. For example, the user interface device can be used to access data and applications hosted by database system 16, and to perform searches on stored data, or otherwise allow a user to interact with various GUI pages that may be presented to a user. As discussed above, implementations are suitable for use with the Internet, although other networks can be used instead of or in addition to the Internet, such as an intranet, an extranet, a virtual private network (VPN), a non-TCP/IP based network, any LAN or WAN or the like.

The users of user systems 12 may differ in their respective capacities, and the capacity of a particular user system 12 can be entirely determined by permissions (permission levels) for the current user of such user system. For example, where a salesperson is using a particular user system 12 to interact with the database system 16, that user system can have the capacities allotted to the salesperson. However, while an administrator is using that user system 12 to interact with the database system 16, that user system can have the capacities allotted to that administrator. Where a hierarchical role model is used, users at one permission level can have access to applications, data, and database information accessible by a lower permission level user, but may not have access to certain applications, database information, and data accessible by a user at a higher permission level. Thus, different users generally will have different capabilities with regard to accessing and modifying application and database information, depending on the users' respective security or permission levels (also referred to as “authorizations”).

According to some implementations, each user system 12 and some or all of its components are operator-configurable using applications, such as a browser, including computer code executed using CPU, such as an Intel Pentium® processor or the like. Similarly, the database system 16 (and additional instances of an MTS, where more than one is present) and all of its components can be operator-configurable using application(s) including computer code to run using the processor system 17, which may be implemented to include a CPU, which may include an Intel Pentium® processor or the like, or multiple CPUs.

The database system 16 includes non-transitory computer-readable storage media having instructions stored thereon that are executable by or used to program a server or other computing system (or collection of such servers or computing systems) to perform some of the implementation of processes described herein. For example, the program code 26 can include instructions for operating and configuring the database system 16 to intercommunicate and to process web pages, applications, and other data and media content as described herein. In some implementations, the program code 26 can be downloadable and stored on a hard disk, but the entire program code, or portions thereof, also can be stored in any other volatile or non-volatile memory medium or device as is well known, such as a ROM or RAM, or provided on any media capable of storing program code, such as any type of rotating media including floppy disks, optical discs, DVDs, CDs, microdrives, magneto-optical discs, magnetic or optical cards, nanosystems (including molecular memory integrated circuits), or any other type of computer-readable medium or device suitable for storing instructions or data. Additionally, the entire program code, or portions thereof, may be transmitted and downloaded from a software source over a transmission medium, for example, over the Internet, or from another server, as is well known, or transmitted over any other existing network connection as is well known (for example, extranet, VPN, LAN, etc.) using any communication medium and protocols (for example, TCP/IP, HTTP, HTTPS, Ethernet, etc.) as are well known. It will also be appreciated that computer code for the disclosed implementations can be realized in any programming language that can be executed on a server or other computing system such as, for example, C, C++, HTML, any other markup language, Java™ JavaScript, ActiveX, any other scripting language, such as VBScript, and many other programming languages as are well known.

FIG. 1B shows a block diagram of example implementations of elements of FIG. 1A and example interconnections between these elements according to some implementations. That is, FIG. 1B also illustrates environment 10, but FIG. 1B, various elements of the database system 16 and various interconnections between such elements are shown with more specificity according to some more specific implementations. In some implementations, the database system 16 may not have the same elements as those described herein or may have other elements instead of, or in addition to, those described herein.

In FIG. 1B, the user system 12 includes a processor system 12A, a memory system 12B, an input system 12C, and an output system 12D. The processor system 12A can include any suitable combination of one or more processors. The memory system 12B can include any suitable combination of one or more memory devices. The input system 12C can include any suitable combination of input devices, such as one or more touchscreen interfaces, keyboards, mice, trackballs, scanners, cameras, or interfaces to networks. The output system 12D can include any suitable combination of output devices, such as one or more display devices, printers, or interfaces to networks.

In FIG. 1B, the network interface 20 is implemented as a set of HTTP application servers 100 ₁-100 _(N). Each application server 100, also referred to herein as an “app server,” is configured to communicate with tenant database 22 and the tenant data 23 therein, as well as system database 24 and the system data 25 therein, to serve requests received from the user systems 12. The tenant data 23 can be divided into individual tenant storage spaces 112, which can be physically or logically arranged or divided. Within each tenant storage space 112, user storage 114, and application metadata 116 can similarly be allocated for each user. For example, a copy of a user's most recently used (MRU) items can be stored to user storage 114. Similarly, a copy of MRU items for an entire organization that is a tenant can be stored to tenant storage space 112.

The database system 16 also includes a user interface (UI) 30 and an application programming interface (API) 32. The process space 28 includes system process space 102, individual tenant process spaces 104 and a tenant management process space 110. The application platform 18 includes an application setup mechanism 38 that supports application developers' creation and management of applications. Such applications and others can be saved as metadata into tenant database 22 by save routines 36 for execution by subscribers as one or more tenant process spaces 104 managed by tenant management process space 110, for example. Invocations to such applications can be coded using PL/SOQL 34, which provides a programming language style interface extension to the API 32. A detailed description of some PL/SOQL language implementations is discussed in commonly assigned U.S. Pat. No. 7,730,478, titled METHOD AND SYSTEM FOR ALLOWING ACCESS TO DEVELOPED APPLICATIONS VIA A MULTI-TENANT ON-DEMAND DATABASE SERVICE, issued on Jun. 1, 2010, and hereby incorporated by reference herein in its entirety and for all purposes. Invocations to applications can be detected by one or more system processes, which manage retrieving application metadata 116 for the subscriber making the invocation and executing the metadata as an application in a virtual machine.

Each application server 100 can be communicably coupled with tenant database 22 and system database 24, for example, having access to tenant data 23 and system data 25, respectively, via a different network connection. For example, one application server 100 ₁ can be coupled via the network 14 (for example, the Internet), another application server 100 ₂ can be coupled via a direct network link, and another application server 100 _(N) can be coupled by yet a different network connection. Transfer Control Protocol and Internet Protocol (TCP/IP) are examples of typical protocols that can be used for communicating between application servers 100 and the database system 16. However, it will be apparent to one skilled in the art that other transport protocols can be used to optimize the database system 16 depending on the network interconnections used.

In some implementations, each application server 100 is configured to handle requests for any user associated with any organization that is a tenant of the database system 16. Because it can be desirable to be able to add and remove application servers 100 from the server pool at any time and for various reasons, in some implementations there is no server affinity for a user or organization to a specific application server 100. In some such implementations, an interface system implementing a load balancing function (for example, an F5 Big-IP load balancer) is communicably coupled between the application servers 100 and the user systems 12 to distribute requests to the application servers 100. In one implementation, the load balancer uses a least-connections algorithm to route user requests to the application servers 100. Other examples of load balancing algorithms, such as round robin and observed-response-time, also can be used. For example, in some instances, three consecutive requests from the same user could hit three different application servers 100, and three requests from different users could hit the same application server 100. In this manner, by way of example, database system 16 can be a multi-tenant system in which database system 16 handles storage of, and access to, different objects, data, and applications across disparate users and organizations.

In one example storage use case, one tenant can be a company that employs a sales force where each salesperson uses database system 16 to manage aspects of their sales. A user can maintain contact data, leads data, customer follow-up data, performance data, goals and progress data, etc., all applicable to that user's personal sales process (for example, in tenant database 22). In an example of a MTS arrangement, because all of the data and the applications to access, view, modify, report, transmit, calculate, etc., can be maintained and accessed by a user system 12 having little more than network access, the user can manage his or her sales efforts and cycles from any of many different user systems. For example, when a salesperson is visiting a customer and the customer has Internet access in their lobby, the salesperson can obtain critical updates regarding that customer while waiting for the customer to arrive in the lobby.

While each user's data can be stored separately from other users' data regardless of the employers of each user, some data can be organization-wide data shared or accessible by several users or all of the users for a given organization that is a tenant. Thus, there can be some data structures managed by database system 16 that are allocated at the tenant level while other data structures can be managed at the user level. Because an MTS can support multiple tenants including possible competitors, the MTS can have security protocols that keep data, applications, and application use separate. Also, because many tenants may opt for access to an MTS rather than maintain their own system, redundancy, up-time, and backup are additional functions that can be implemented in the MTS. In addition to user-specific data and tenant-specific data, the database system 16 also can maintain system level data usable by multiple tenants or other data. Such system level data can include industry reports, news, postings, and the like that are sharable among tenants.

In some implementations, the user systems 12 (which also can be client systems) communicate with the application servers 100 to request and update system-level and tenant-level data from the database system 16. Such requests and updates can involve sending one or more queries to tenant database 22 or system database 24. The database system 16 (for example, an application server 100 in the database system 16) can automatically generate one or more SQL statements (for example, one or more SQL queries) designed to access the desired information. System database 24 can generate query plans to access the requested data from the database. The term “query plan” generally refers to one or more operations used to access information in a database system.

Each database can generally be viewed as a collection of objects, such as a set of logical tables, containing data fitted into predefined or customizable categories. A “table” is one representation of a data object, and may be used herein to simplify the conceptual description of objects and custom objects according to some implementations. It should be understood that “table” and “object” may be used interchangeably herein. Each table generally contains one or more data categories logically arranged as columns or fields in a viewable schema. Each row or element of a table can contain an instance of data for each category defined by the fields. For example, a CRM database can include a table that describes a customer with fields for basic contact information such as name, address, phone number, fax number, etc. Another table can describe a purchase order, including fields for information such as customer, product, sale price, date, etc. In some MTS implementations, standard entity tables can be provided for use by all tenants. For CRM database applications, such standard entities can include tables for case, account, contact, lead, and opportunity data objects, each containing pre-defined fields. As used herein, the term “entity” also may be used interchangeably with “object” and “table.”

In some MTS implementations, tenants are allowed to create and store custom objects, or may be allowed to customize standard entities or objects, for example by creating custom fields for standard objects, including custom index fields. Commonly assigned U.S. Pat. No. 7,779,039, titled CUSTOM ENTITIES AND FIELDS IN A MULTI-TENANT DATABASE SYSTEM, issued on Aug. 17, 2010, and hereby incorporated by reference herein in its entirety and for all purposes, teaches systems and methods for creating custom objects as well as customizing standard objects in a multi-tenant database system. In some implementations, for example, all custom entity data rows are stored in a single multi-tenant physical table, which may contain multiple logical tables per organization. It is transparent to customers that their multiple “tables” are in fact stored in one large table or that their data may be stored in the same table as the data of other customers.

FIG. 2A shows a system diagram illustrating example architectural components of an on-demand database service environment 200 according to some implementations. A client machine communicably connected with the cloud 204, generally referring to one or more networks in combination, as described herein, can communicate with the on-demand database service environment 200 via one or more edge routers 208 and 212. A client machine can be any of the examples of user systems 12 described above. The edge routers can communicate with one or more core switches 220 and 224 through a firewall 216. The core switches can communicate with a load balancer 228, which can distribute server load over different pods, such as the pods 240 and 244. The pods 240 and 244, which can each include one or more servers or other computing resources, can perform data processing and other operations used to provide on-demand services. Communication with the pods can be conducted via pod switches 232 and 236. Components of the on-demand database service environment can communicate with database storage 256 through a database firewall 248 and a database switch 252.

As shown in FIGS. 2A and 2B, accessing an on-demand database service environment can involve communications transmitted among a variety of different hardware or software components. Further, the on-demand database service environment 200 is a simplified representation of an actual on-demand database service environment. For example, while only one or two devices of each type are shown in FIGS. 2A and 2B, some implementations of an on-demand database service environment can include anywhere from one to several devices of each type. Also, the on-demand database service environment need not include each device shown in FIGS. 2A and 2B, or can include additional devices not shown in FIGS. 2A and 2B.

Additionally, it should be appreciated that one or more of the devices in the on-demand database service environment 200 can be implemented on the same physical device or on different hardware. Some devices can be implemented using hardware or a combination of hardware and software. Thus, terms such as “data processing apparatus,” “machine,” “server,” “device,” and “processing device” as used herein are not limited to a single hardware device; rather, references to these terms can include any suitable combination of hardware and software configured to provide the described functionality.

The cloud 204 is intended to refer to a data network or multiple data networks, often including the Internet. Client machines communicably connected with the cloud 204 can communicate with other components of the on-demand database service environment 200 to access services provided by the on-demand database service environment. For example, client machines can access the on-demand database service environment to retrieve, store, edit, or process information. In some implementations, the edge routers 208 and 212 route packets between the cloud 204 and other components of the on-demand database service environment 200. For example, the edge routers 208 and 212 can employ the Border Gateway Protocol (BGP). The BGP is the core routing protocol of the Internet. The edge routers 208 and 212 can maintain a table of Internet Protocol (IP) networks or ‘prefixes,’ which designate network reachability among autonomous systems on the Internet.

In some implementations, the firewall 216 can protect the inner components of the on-demand database service environment 200 from Internet traffic. The firewall 216 can block, permit, or deny access to the inner components of the on-demand database service environment 200 based upon a set of rules and other criteria. The firewall 216 can act as one or more of a packet filter, an application gateway, a stateful filter, a proxy server, or any other type of firewall.

In some implementations, the core switches 220 and 224 are high-capacity switches that transfer packets within the on-demand database service environment 200. The core switches 220 and 224 can be configured as network bridges that quickly route data between different components within the on-demand database service environment. In some implementations, the use of two or more core switches 220 and 224 can provide redundancy or reduced latency.

In some implementations, the pods 240 and 244 perform the core data processing and service functions provided by the on-demand database service environment. Each pod can include various types of hardware or software computing resources. An example of the pod architecture is discussed in greater detail with reference to FIG. 2B. In some implementations, communication between the pods 240 and 244 is conducted via the pod switches 232 and 236. The pod switches 232 and 236 can facilitate communication between the pods 240 and 244 and client machines communicably connected with the cloud 204, for example, via core switches 220 and 224. Also, the pod switches 232 and 236 may facilitate communication between the pods 240 and 244 and the database storage 256. In some implementations, the load balancer 228 can distribute workload between the pods 240 and 244. Balancing the on-demand service requests between the pods can assist in improving the use of resources, increasing throughput, reducing response times, or reducing overhead. The load balancer 228 may include multilayer switches to analyze and forward traffic.

In some implementations, access to the database storage 256 is guarded by a database firewall 248. The database firewall 248 can act as a computer application firewall operating at the database application layer of a protocol stack. The database firewall 248 can protect the database storage 256 from application attacks such as SQL injection, database rootkits, and unauthorized information disclosure. In some implementations, the database firewall 248 includes a host using one or more forms of reverse proxy services to proxy traffic before passing it to a gateway router. The database firewall 248 can inspect the contents of database traffic and block certain content or database requests. The database firewall 248 can work on the SQL application level atop the TCP/IP stack, managing applications' connection to the database or SQL management interfaces as well as intercepting and enforcing packets traveling to or from a database network or application interface.

In some implementations, communication with the database storage 256 is conducted via the database switch 252. The multi-tenant database storage 256 can include more than one hardware or software components for handling database queries. Accordingly, the database switch 252 can direct database queries transmitted by other components of the on-demand database service environment (for example, the pods 240 and 244) to the correct components within the database storage 256. In some implementations, the database storage 256 is an on-demand database system shared by many different organizations as described above with reference to FIGS. 1A and 1B.

FIG. 2B shows a system diagram further illustrating example architectural components of an on-demand database service environment according to some implementations. The pod 244 can be used to render services to a user of the on-demand database service environment 200. In some implementations, each pod includes a variety of servers or other systems. The pod 244 includes one or more content batch servers 264, content search servers 268, query servers 282, file servers 286, access control system (ACS) servers 280, batch servers 284, and app servers 288. The pod 244 also can include database instances 290, quick file systems (QFS) 292, and indexers 294. In some implementations, some or all communication between the servers in the pod 244 can be transmitted via the pod switch 236.

In some implementations, the app servers 288 include a hardware or software framework dedicated to the execution of procedures (for example, programs, routines, scripts) for supporting the construction of applications provided by the on-demand database service environment 200 via the pod 244. In some implementations, the hardware or software framework of an app server 288 is configured to execute operations of the services described herein, including performance of the blocks of various methods or processes described herein. In some alternative implementations, two or more app servers 288 can be included and cooperate to perform such methods, or one or more other servers described herein can be configured to perform the disclosed methods.

The content batch servers 264 can handle requests internal to the pod. Some such requests can be long-running or not tied to a particular customer. For example, the content batch servers 264 can handle requests related to log mining, cleanup work, and maintenance tasks. The content search servers 268 can provide query and indexer functions. For example, the functions provided by the content search servers 268 can allow users to search through content stored in the on-demand database service environment. The file servers 286 can manage requests for information stored in the file storage 298. The file storage 298 can store information such as documents, images, and binary large objects (BLOBs). By managing requests for information using the file servers 286, the image footprint on the database can be reduced. The query servers 282 can be used to retrieve information from one or more file systems. For example, the query servers 282 can receive requests for information from the app servers 288 and transmit information queries to the network file systems (NFS) 296 located outside the pod.

The pod 244 can share a database instance 290 configured as a multi-tenant environment in which different organizations share access to the same database. Additionally, services rendered by the pod 244 may call upon various hardware or software resources. In some implementations, the ACS servers 280 control access to data, hardware resources, or software resources. In some implementations, the batch servers 284 process batch jobs, which are used to run tasks at specified times. For example, the batch servers 284 can transmit instructions to other servers, such as the app servers 288, to trigger the batch jobs.

In some implementations, the QFS 292 is an open source file system available from Sun Microsystems, Inc. The QFS can serve as a rapid-access file system for storing and accessing information available within the pod 244. The QFS 292 can support some volume management capabilities, allowing many disks to be grouped together into a file system. File system metadata can be kept on a separate set of disks, which can be useful for streaming applications where long disk seeks cannot be tolerated. Thus, the QFS system can communicate with one or more content search servers 268 or indexers 294 to identify, retrieve, move, or update data stored in the NFS 296 or other storage systems.

In some implementations, one or more query servers 282 communicate with the NFS 296 to retrieve or update information stored outside of the pod 244. The NFS 296 can allow servers located in the pod 244 to access information to access files over a network in a manner similar to how local storage is accessed. In some implementations, queries from the query servers 282 are transmitted to the NFS 296 via the load balancer 228, which can distribute resource requests over various resources available in the on-demand database service environment. The NFS 296 also can communicate with the QFS 292 to update the information stored on the NFS 296 or to provide information to the QFS 292 for use by servers located within the pod 244.

In some implementations, the pod includes one or more database instances 290. The database instance 290 can transmit information to the QFS 292. When information is transmitted to the QFS, it can be available for use by servers within the pod 244 without using an additional database call. In some implementations, database information is transmitted to the indexer 294. Indexer 294 can provide an index of information available in the database instance 290 or QFS 292. The index information can be provided to the file servers 286 or the QFS 292.

FIG. 3 illustrates a diagrammatic representation of a machine in the exemplary form of a computer system 300 within which a set of instructions (e.g., for causing the machine to perform any one or more of the methodologies discussed herein) may be executed. In alternative implementations, the machine may be connected (e.g., networked) to other machines in a LAN, a WAN, an intranet, an extranet, or the Internet. The machine may operate in the capacity of a server or a client machine in client-server network environment, or as a peer machine in a peer-to-peer (or distributed) network environment. The machine may be a personal computer (PC), a tablet PC, a set-top box (STB), a PDA, a cellular telephone, a web appliance, a server, a network router, switch or bridge, or any machine capable of executing a set of instructions (sequential or otherwise) that specify actions to be taken by that machine. Further, while only a single machine is illustrated, the term “machine” shall also be taken to include any collection of machines that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies discussed herein. Some or all of the components of the computer system 300 may be utilized by or illustrative of any of the electronic components described herein (e.g., any of the components illustrated in or described with respect to FIGS. 1A, 1B, 2A, and 2B).

The exemplary computer system 300 includes a processing device (processor) 302, a main memory 304 (e.g., ROM, flash memory, dynamic random access memory (DRAM) such as synchronous DRAM (SDRAM) or Rambus DRAM (RDRAM), etc.), a static memory 306 (e.g., flash memory, static random access memory (SRAM), etc.), and a data storage device 320, which communicate with each other via a bus 310.

Processor 302 represents one or more general-purpose processing devices such as a microprocessor, central processing unit, or the like. More particularly, the processor 302 may be a complex instruction set computing (CISC) microprocessor, reduced instruction set computing (RISC) microprocessor, very long instruction word (VLIW) microprocessor, or a processor implementing other instruction sets or processors implementing a combination of instruction sets. The processor 302 may also be one or more special-purpose processing devices such as an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a digital signal processor (DSP), network processor, or the like. The processor 302 is configured to execute instructions 340 for performing the operations and steps discussed herein.

The computer system 300 may further include a network interface device 308. The computer system 300 also may include a video display unit 312 (e.g., a liquid crystal display (LCD), a cathode ray tube (CRT), or a touch screen), an alphanumeric input device 314 (e.g., a keyboard), a cursor control device 316 (e.g., a mouse), and a signal generation device 322 (e.g., a speaker).

Power device 318 may monitor a power level of a battery used to power the computer system 300 or one or more of its components. The power device 318 may provide one or more interfaces to provide an indication of a power level, a time window remaining prior to shutdown of computer system 300 or one or more of its components, a power consumption rate, an indicator of whether computer system is utilizing an external power source or battery power, and other power related information. In some implementations, indications related to the power device 318 may be accessible remotely (e.g., accessible to a remote back-up management module via a network connection). In some implementations, a battery utilized by the power device 318 may be an uninterruptable power supply (UPS) local to or remote from computer system 300. In such implementations, the power device 318 may provide information about a power level of the UPS.

The data storage device 320 may include a computer-readable storage medium 324 (e.g., a non-transitory computer-readable storage medium) on which is stored one or more sets of instructions 340 (e.g., software) embodying any one or more of the methodologies or functions described herein. These instructions 340 may also reside, completely or at least partially, within the main memory 304 and/or within the processor 302 during execution thereof by the computer system 300, the main memory 304, and the processor 302 also constituting computer-readable storage media. The instructions 340 may further be transmitted or received over a network 330 (e.g., the network 14) via the network interface device 308. While the computer-readable storage medium 324 is shown in an exemplary implementation to be a single medium, it is to be understood that the computer-readable storage medium 324 may include a single medium or multiple media (e.g., a centralized or distributed database, and/or associated caches and servers) that store the one or more sets of instructions 340.

For simplicity of explanation, the methods of this disclosure are depicted and described as a series of acts. However, acts in accordance with this disclosure can occur in various orders and/or concurrently, and with other acts not presented and described herein. Furthermore, not all illustrated acts may be required to implement the methods in accordance with the disclosed subject matter. In addition, those skilled in the art will understand and appreciate that the methods could alternatively be represented as a series of interrelated states via a state diagram or events. Additionally, it should be appreciated that the methods disclosed in this specification are capable of being stored on an article of manufacture to facilitate transporting and transferring instructions for performing such methods to computing devices. The term “article of manufacture,” as used herein, is intended to encompass a computer program accessible from any computer-readable device or storage media.

Anomaly Detection and Root Cause Analysis

Certain implementations of the present disclosure provide an anomaly detection framework that identifies relevant changes in infrastructure performance as they relate to pod-level or host-level trends in key performance metrics. The implementations automatically separate unexpected features in performance activity signals from daily trends and provide context to understand how such events arise and what combinations of complex factors were the likely causes of the detected features. A prioritization mechanism is utilized to highlight anomalies that are most severe while eliminating false positives, such as a one-time or infrequently occurring spike in the activity signal.

In some implementations, the prioritization is derived by assigning to each anomaly a priority score computed as a standardized score combining various measures. For example, a standardized score may be computed from a combination of (e.g., a normalized weighted sum of) a change of slope, a change in the level shift, and an extent and duration of an infrastructure spike or an infrastructure event. Such prioritization helps infrastructure engineering teams to determine, for example, whether the anomaly was a one-time occurrence or if it is indicative of an ongoing trend. Once the anomaly is identified, correlation analysis is performed to identify the most likely root cause of the anomaly, such as an increase in overall workload, a software release, a change in hardware configuration, a load imbalance, or some other cause. In some implementations, a priority score indicative of severity is computed for each anomaly which is compared to other anomalies or measured changes in the activity signal, with an underlying time period of the anomaly being flagged for analysis.

The implementations may be advantageously utilized to determine the following: (1) which anomalies can be safely ignored and which ones require action; (2) what time period the anomaly spans; (3) what is the most likely explanation for the anomaly; (4) what organizations within the multi-tenant environment drive the key performance metrics related to the anomaly; and (5) whether the anomaly is a result of a load imbalance among the hosts. In some implementations, the anomaly detection is performed using change point detection algorithms for time-series analysis of the activity signals. This may include, for example, historical change point data for slope changes and level shifts, as well as techniques for detection of anomalies in the time-series.

FIG. 4 illustrates an exemplary process flow 400 for anomaly detection, prioritization, and correlation according to some implementations. Initially, a baseline signal is removed from the activity signal at block 410. For example, if the activity signal corresponds to a time period on the scale of days or weeks, a weekly seasonality is removed by smoothing the data. Smoothing can be performed, for example, by computing a weekly maximum and applying a running medium to the weekly maximum, which establishes a baseline representing organic resource consumption.

Once the baseline signal has been removed, at block 420 one of several types of changes observed in the activity signal may be classified as anomalies. These changes include, but are not limited to, spikes, slope changes, level shifts, and load imbalances. In some implementations, anomaly detection is performed using a piecewise aggregate approximation (PAA) algorithm to reduce the activity signal time-series to its dimensionality. The algorithm segments the activity signal into several equally sized frames and then computes a mean for each frame. The frames are then converted into a symbolic aggregate approximation (SAX) by producing symbols corresponding to time-series features with equal probability. An underlying assumption of SAX is that values follow a normal distribution such that the symbol used to represent various intervals of values is equally probable under the normal distribution. These symbols index the time-series and allow it to be easily searched and matched. Once the SAX representation is computed, Laplacian smoothing is used to eliminate zero-probability events and assign additional weight to rare events. In some implementations, or more of a p-value, a log-likelihood, or a rate ratio is computed to determine the probability of observing an anomalous count in a particular time period. This is performed by combining the total number of windows with the number of instances for a particular combination of SAX symbols with the cardinality of the SAX space. The p-value, for example, indicates how anomalous a particular combination of SAX symbols and its associated time period are with respect to time-series represented in the data.

Reference is now made to FIGS. 5A-5D, which illustrate examples of detected anomalies in an activity signal. FIG. 5A illustrates the detection of a spike anomaly according to some implementations. Spikes may be detected, for example, by performing PAA analysis on the activity signal in order to reduce its dimensionality into segments. Each segment is z-normalized and scored using SAX. In some implementations, scores exceeding a predefined threshold are categorized as spikes.

FIG. 5B illustrates the detection of a slope change anomaly according to some implementations. Slope changes are most often correlated with transaction increases/decreases and organization counts. In some implementations, slope changes are detected as changes in the mean (distinguishable from mere variability in the activity signal) using binary segmentation.

FIG. 5C illustrates the detection of a level shift anomaly according to some implementations. Level shifts are most often correlated with transactions or release events. In some implementations, level shifts are detected as large changes in the mean absolute deviation (MAD) of the activity signal.

FIG. 5D illustrates the detection of a host imbalance anomaly according to some implementations. Load imbalances may be detected by differentiating each host's workload from the median workload on the pod for a given host type. These differences are then summed over time and the imbalanced hosts are observed to have a significantly larger sum.

Referring once again to FIG. 4, at block 430 a priority score is computed for each anomaly which may be used to sort the anomalies based on severity. The priority score may be representative of severity of the anomaly. In some implementations, for a given anomaly, the outputs of the methods used to classify the various changes described with respect to FIGS. 5A-5D are combined and normalized for the associated time period. Each anomaly may be characterized by multiple detected changes in the activity signal. For example, a level shift may be accompanied by a detectable slope change. For two anomalies with comparable level shifts, the anomaly having a steeper slope change would likely receive a higher priority score than the anomaly having a shallower slope change.

At block 440 the underlying time periods of the anomalies detected in block 420 are then selected for correlation against a list of performance metrics in block 450, which may be provided by capacity planners and performance engineers. The performance metrics may include changes in workload, software releases, changes in hardware configurations, and identified load imbalances. At block 460, some or all anomalies and their correlations can be visualized in a UI, as discussed below with respect to FIG. 6. In the case of anomalies related to load imbalances, automated remediation may be triggered at block 470. For example, a remediation signal may be generated for such anomalies that triggers a partition re-balance. In some implementations, the remediation signal comprises information pertaining to the type of hardware needed to alleviate a load imbalance or capacity tightness.

FIG. 6 illustrates an exemplary UI 600 for visualizing anomalies and their correlations to performance metrics according to some implementations. The UI 600 includes an anomaly listing window 602 and an analysis window 607. The anomaly listing window includes a list of detected anomalies in tabular form. Each row corresponds to a particular anomaly, which may include descriptive data such as a priority score indicative of severity (e.g., high/medium/low, a numerical score, etc.), an indicator of a pod for which an activity signal was analyzed, a relationship correlated to the detected anomaly (e.g., a software release, an increase/decrease in organization count, an increase/decrease in transactions, etc.), and a time period indicated by a start time and an end time. In some implementations, fewer descriptive data elements may be included, or other data elements other than those shown may be included. The listing of anomalies may be arranged and displayed in any desired order. For example, the anomalies shown are arranged in an order of severity. The anomalies correspond to those detected in an application CPU time activity signal, though it is to be understood that other types of activity signals indicative of resource utilization or some other metric may be utilized. In some implementations, one or more anomalies in the listing may corresponds to other types of activity signals.

In some implementations, multiple anomalies may be detected in the same activity signal (i.e., within a data-series corresponding to the same or overlapping time period). For example, the listing includes two anomalies detected in an activity signal for POD40, which may be correlated to different root causes. As another example, different activity signals for different pods may be measured during the same or overlapping time period.

As illustrated, anomaly 604 is selected in the anomaly listing window 602, which results in details related to anomaly 604 being displayed in the analysis window 607. The analysis window 607 includes a summary window 608 and a plot window 610. The summary window 608 includes contextual data descriptive of the anomaly, including a verbal summary, a list of associated host devices and organizations associated with the time period during which the anomaly was detected. In some implementations, the verbal summary is auto-generated based on a template that utilizes pre-defined language and sentence structure that is selected based on the results of the correlation analysis.

The plot window 610 includes two plots, though more or less plots may be included. The plot on the left shows application CPU time (left axis) over a multi-day time period plotted against major software releases (right axis) over that same time period. Including both of these data-series in the same plot allows for a user to visualize the correlation between the detected anomaly in the activity signal and the conditions of the multi-tenant environment that likely caused the anomaly. An overlay 612 is further included to indicate the time period corresponding to the identified anomaly 604, which in this example corresponds to a level shift. The plot on the right shows a plot of the same data as the plot on the left, except that application CPU time is now plotted as a function of the pre-event day and the post-event day to allow the user to visualize a change in measured app CPU time before and after the correlated event (i.e., a major product release in the present example).

In some implementations, multiple anomalies may be selected in the anomaly listing window 602, which may result in additional information being displayed for each selected anomaly in the analysis window 607. For example, the selected anomalies may be displayed in additional plots or overlaid in the same plot.

Reference is now made to FIG. 7, which is a flow diagram illustrating an exemplary method 700 for performing anomaly detection and root cause analysis according to some implementations. The method 700 may be performed by processing logic comprising hardware (e.g., circuitry, dedicated logic, programmable logic, microcode, etc.), software (such as instructions run on a processing device), or a combination thereof. In some implementations, the method 700 may be performed by a database system (e.g., the database system 16). It is to be understood that these implementations are merely exemplary, and that other devices may perform some or all of the functionality described.

Referring to FIG. 7, at block 710, a processing device (e.g., a processing device of a database system 16) receives an activity signal representative of resource utilization within a multi-tenant environment. In some implementations, the activity signal corresponds to an application CPU time signal. The activity signal is measured across a time period, and may be a historical activity signal corresponding to a previous time period or a real-time activity signal.

At block 720, the processing device removes a baseline signal from the activity signal to generate a corrected activity signal. In some implementations, the baseline signal is computed from a predicted amount of resource utilization occurring during a time period associated with the activity signal. In some implementations, the baseline signal is computed based on historical resource utilization data.

At block 730, the processing device detects a plurality of anomalies in the corrected activity signal. In some implementations, detecting the plurality of anomalies comprises identifying, within the corrected activity signal, measurable changes in the corrected activity signal selected from a level shift, a slope change, a spike, or a load imbalance. In some implementations, a binary segmentation algorithm is used to detect relevant slope changes in the activity signal. In some implementations, the processing device stores information descriptive of the detected anomalies. The stored information may be utilized, in some implementations, to train a machine learning model to detect anomalies in activity signals.

At block 740, the processing device computes a priority score for each of the plurality of anomalies. In some implementations, assigning the priority score comprises computing a priority score for each anomaly based on a normalized intensity of the measurable changes in the corrected activity signal for a given anomaly.

At block 750, the processing device correlates, based on the computed priority scores, at least a subset of the plurality of anomalies to one or more performance metrics of the multi-tenant environment. In some implementations, the selected subset corresponds to anomalies having computed priority scores that satisfy a threshold condition indicative of severity. In some implementations, the remaining anomalies that fail to satisfy the threshold condition may be ignored and/or omitted from analysis or visualization. Such anomalies may be designated as low priority or false positives. In some implementations, for each anomaly of the subset, the processing device identifies a time period associated with the activity signal within which the anomaly was identified, and determines an association at different time lags between the anomaly and an event occurring within the multi-tenant environment during or substantially close to the time period. For example, an event that is substantially close to the time period may be, for example, within 20% of the limits of the time period based on a total length of the time period (e.g., a 10-day time period would consider events for correlation purposes within 2 days outside of that time period). As another example, a detectable time lag may occur between an anomaly in a time series (e.g., a spike at minute 5 of the time series) and another event that manifests itself at a later time (e.g., an event occurring at minute 12 of the time series).

At block 760, the processing device transmits a remediation signal to one or more devices (e.g., host servers) in the multi-tenant environment, for example, based on the correlations and the priority scores. In some implementations, responsive to determining that an anomaly of the plurality of anomalies is correlated to a hardware-related load imbalance, the processing device transmits to the one or more devices to trigger a load re-balance.

In some implementations, the processing device transmits, to a device for visualization, data descriptive of the plurality of anomalies, the priority scores, and the correlations to the one or more performance metrics, wherein the device is to generate for display a visual representation of the plurality of anomalies, the priority scores, and the correlations (e.g., as illustrated by UI 600).

In the foregoing description, numerous details are set forth. It will be apparent, however, to one of ordinary skill in the art having the benefit of this disclosure, that the present disclosure may be practiced without these specific details. While specific implementations have been described herein, it should be understood that they have been presented by way of example only, and not limitation. The breadth and scope of the present application should not be limited by any of the implementations described herein, but should be defined only in accordance with the following and later-submitted claims and their equivalents. Indeed, other various implementations of and modifications to the present disclosure, in addition to those described herein, will be apparent to those of ordinary skill in the art from the foregoing description and accompanying drawings. Thus, such other implementations and modifications are intended to fall within the scope of the present disclosure.

Furthermore, although the present disclosure has been described herein in the context of a particular implementation in a particular environment for a particular purpose, those of ordinary skill in the art will recognize that its usefulness is not limited thereto and that the present disclosure may be beneficially implemented in any number of environments for any number of purposes. Accordingly, the claims set forth below should be construed in view of the full breadth and spirit of the present disclosure as described herein, along with the full scope of equivalents to which such claims are entitled. 

What is claimed is:
 1. A computer-implemented method comprising: receiving an activity signal representative of resource utilization within a multi-tenant environment; removing a baseline signal from the activity signal to generate a corrected activity signal; detecting a plurality of anomalies in the corrected activity signal; computing a priority score for each of the plurality of anomalies; correlating, based on the priority scores, at least a subset of the plurality of anomalies to one or more performance metrics of the multi-tenant environment; and transmitting a remediation signal to one or more devices in the multi-tenant environment based on the correlations and the priority scores.
 2. The method of claim 1, wherein the baseline signal is computed from a predicted amount of resource utilization occurring during a time period associated with the activity signal.
 3. The method of claim 1, wherein detecting the plurality of anomalies comprises identifying, within the corrected activity signal, measurable changes in the corrected activity signal selected from a level shift, a slope change, a spike, or a load imbalance.
 4. The method of claim 3, wherein computing the priority score for each of the plurality of anomalies comprises: computing the priority score for each anomaly based on a normalized intensity of the measurable changes in the corrected activity signal for a given anomaly; and selecting the subset of the plurality of anomalies for correlating to the one or more performance metrics, wherein the selected subset corresponds to anomalies having computed priority scores that satisfy a threshold condition indicative of severity.
 5. The method of claim 4, wherein correlating the subset of the plurality of anomalies to the one or more performance metrics of the multi-tenant environment comprises: for each anomaly of the subset, identifying a time period associated with the activity signal within which the anomaly was identified; and determining at different time lags a correlation between the anomaly and an event occurring within the multi-tenant environment during or substantially close to the time period.
 6. The method of claim 1, wherein transmitting the remediation signal to the one or more devices in the multi-tenant environment based on the correlations and the priority scores comprises: responsive to determining that an anomaly of the plurality of anomalies is correlated to a hardware-related load imbalance, transmitting the remediation signal to the one or more devices to trigger a load re-balance.
 7. The method of claim 1, further comprising: transmitting, to a device for visualization, data descriptive of the plurality of anomalies, the priority scores, and the correlations to the one or more performance metrics, wherein the device is to generate for display a visual representation of the plurality of anomalies, the priority scores, and the correlations.
 8. A system comprising: a processing device; and a memory device coupled to the processing device, the memory device having instructions stored thereon that, in response to execution by the processing device, cause the processing device to: receive an activity signal representative of resource utilization within a multi-tenant environment; remove a baseline signal from the activity signal to generate a corrected activity signal; detect a plurality of anomalies in the corrected activity signal; assign a priority score to each of the plurality of anomalies; correlate, based on the computed priority scores, at least a subset of the plurality of anomalies to one or more performance metrics of the multi-tenant environment; and transmit a remediation signal to one or more devices in the multi-tenant environment based on the correlations and the priority scores.
 9. The system of claim 8, wherein the baseline signal is computed from a predicted amount of resource utilization occurring during a time period associated with the activity signal.
 10. The system of claim 8, wherein to detect the plurality of anomalies, the processing device is to further: identify, within the corrected activity signal, measurable changes in the corrected activity signal selected from a level shift, a slope change, a spike, or a load imbalance.
 11. The system of claim 10, wherein to compute the priority score for each of the plurality of anomalies, the processing device is to further: compute the priority score for each anomaly based on a normalized intensity of the measurable changes in the corrected activity signal for a given anomaly; and select the subset of the plurality of anomalies for correlating to the one or more performance metrics, wherein the selected subset corresponds to anomalies having computed priority scores that satisfy a threshold condition indicative of severity.
 12. The system of claim 11, wherein to correlate the subset of the plurality of anomalies to the one or more performance metrics of the multi-tenant environment, the processing device is to further: for each anomaly of the subset, identify a time period associated with the activity signal within which the anomaly was identified; and determine at different time lags a correlation between the anomaly and an event occurring within the multi-tenant environment during or substantially close to the time period.
 13. The system of claim 8, wherein to transmit the remediation signal to the one or more devices in the multi-tenant environment based on the correlations and the priority scores, the processing device is to further: transmit the remediation signal to the one or more devices to trigger a load re-balance responsive to determining that an anomaly of the plurality of anomalies is correlated to a hardware-related load imbalance.
 14. The system of claim 8, wherein the processing device is to further: transmit, to a device for visualization, data descriptive of the plurality of anomalies, the priority scores, and the correlations to the one or more performance metrics, wherein the device is to generate for display a visual representation of the plurality of anomalies, the priority scores, and the correlations.
 15. A non-transitory computer-readable storage medium having instructions encoded thereon which, when executed by a processing device, cause the processing device to: receive an activity signal representative of resource utilization within a multi-tenant environment; remove a baseline signal from the activity signal to generate a corrected activity signal; detect a plurality of anomalies in the corrected activity signal; compute a priority score for each of the plurality of anomalies; correlate, based on the computed priority scores, at least a subset of the plurality of anomalies to one or more performance metrics of the multi-tenant environment; and transmit a remediation signal to one or more devices in the multi-tenant environment based on the correlations and the priority scores.
 16. The non-transitory computer-readable storage medium of claim 15, wherein the baseline signal is computed from a predicted amount of resource utilization occurring during a time period associated with the activity signal.
 17. The non-transitory computer-readable storage medium of claim 15, wherein to detect the plurality of anomalies, the processing device is to further: identify, within the corrected activity signal, measurable changes in the corrected activity signal selected from a level shift, a slope change, a spike, or a load imbalance.
 18. The non-transitory computer-readable storage medium of claim 17, wherein to compute the priority score for each of the plurality of anomalies, the processing device is to further: compute the priority score for each anomaly based on a normalized intensity of the measurable changes in the corrected activity signal for a given anomaly; select the subset of the plurality of anomalies for correlating to the one or more performance metrics, wherein the selected subset corresponds to anomalies having computed priority scores that satisfy a threshold condition indicative of severity; for each anomaly of the subset, identify a time period associated with the activity signal within which the anomaly was identified; and determine at different time lags a correlation between the anomaly and an event occurring within the multi-tenant environment during or substantially close to the time period.
 19. The non-transitory computer-readable storage medium of claim 15, wherein to transmit the remediation signal to the one or more devices in the multi-tenant environment based on the correlations and the priority scores, the processing device is to further: transmit the remediation signal to the one or more devices to trigger a load re-balance responsive to determining that an anomaly of the plurality of anomalies is correlated to a hardware-related load imbalance.
 20. The non-transitory computer-readable storage medium of claim 15, wherein the processing device is to further: transmit, to a device for visualization, data descriptive of the plurality of anomalies, the priority scores, and the correlations to the one or more performance metrics, wherein the device is to generate for display a visual representation of the plurality of anomalies, the priority scores, and the correlations. 